How Important is Air Filter Quality When it Comes to HVAC Performance?

October 29, 2015
By
Roth Heating & Cooling, Plumbing & Electrical

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Air filters are not all equal. Generally speaking, most low-end fiberglass
filters barely do an adequate job of keeping the largest airborne particulates
out of your HVAC system. The particles that do get through not only end
up as dirt inside your system, causing it to work inefficiently, but also
recirculating in the supply air and lowering indoor air quality. Here’s
why a better quality air filter might be good for your home.

MERV Ratings

Better quality air filters for residential HVAC systems are usually pleated
and made of dense material to do a better job of capturing particles.
Filters rated by the minimum efficiency reporting value (MERV) system
usually fall within the following categories:

MERV 1-4: Filters capture only the largest particles.

MERV 5-7: Filters do a somewhat better job of trapping smaller particles,
and may be adequate for most households.

MERV 8-12: Filters do an excellent job of capturing most particles found
in a typical household, and also do not significantly slow down airflow.

MERV 13 and above: These filters are usually found in residences where
an occupant has a health issue requiring filtration of even the smallest
particles. Higher efficiency filters may be found in research, hospital
or manufacturing settings. HVAC systems that use this level of filtration
must be modified to allow for reduced airflow.

The key in selecting the right filter for your home is to balance keeping
the smaller particles out of your system’s machinery and out of
your home’s air, while maintaining correct air flow. A filter that
is too dense will cause a condition called pressure drop, and your equipment
will work inefficiently. Pressure drop can also lead to system breakdown.

Electrostatic Filters

Besides the mechanical filtration types described above, you might also
consider electrostatic filters, which catch particles with an electrical
charge. These filters are washable and reusable, so they generally cost
more than mid-level efficiency mechanical filters.

For more on the importance of air filter quality, contact Roth Heating
and Cooling. Our customers recognize us as the top heating, cooling, plumbing,
electrical, drain and appliance service in Portland.